THE ALBUMINS. 305 



acids a reducing substance is set free, it may be assumed that the 

 body in question is mucin. 



Test for Albumoses. To test for albumoses in general, a small 

 amount of the urine is acidified with acetic acid and treated with an 

 equal volume of a saturated solution of common salt. The solution 

 is then boiled and filtered while still hot, so as to remove any coagu- 

 lable albumins that may be present. On cooling, the albumoses 

 separate out, but redissolve on boiling. In such an event, the solu- 

 tion also gives the biuret reaction and that of Millon. 



More exact is the following method, which should always be 

 employed when there is reason to believe that albumoses are present 

 only in traces. The collected twenty-four-hours' urine is carefully 

 neutralized, concentrated to about 1000 c.c. at 60-70 C., filtered, 

 and saturated with ammonium sulphate in substance. The pre- 

 cipitate is collected on a filter, and dissolved in a little water, when 

 a small portion is treated with an equal volume of a saturated solu- 

 tion of common salt, and with acetic acid or nitric acid drop by 

 drop so long as any precipitate that has formed is thus increased. 

 The solution is then boiled. If coagulable albumins are present, 

 these are precipitated, and are filtered off from the hot solution. If 

 the filtrate becomes turbid again on cooling, and clears upon sub- 

 sequent boiling, the presence of albumoses may be inferred. To 

 determine the character of the albumoses in question, the remaining 

 liquid is dialyzed (see above), freed from nucleo-albumin by means 

 of acetic acid, neutralized, concentrated on a water-bath, and 

 treated with an equal volume of a saturated solution of ammonium 

 sulphate. On standing, the primary albumoses are precipitated. 

 The filtrate is then saturated with the salt in substance, when, on 

 further standing, the secondary albumoses separate out. 



True peptones, in the sense of Kiihne, do not occur in the 

 urine, and it is hence unnecessary to describe the older and more 

 complicated methods which formerly were employed in their search. 



Bence Jones' Albumin. This body, as has been pointed out, has 

 repeatedly been encountered in the urine in association with the 

 existence of multiple myelomata of the bones. Of its nature, 

 however, little is known. Most observers have regarded it as an 

 albumose, but it is admitted that it is not identical with any of the 

 known digestive albumoses. Like the globulin described by Paton, 

 it has been found in crystalline form in the urinary sediment, and 

 can be made to crystallize after its isolation in amorphous form. 

 Magnus-Levy, while likewise unable to identify it with any of the 

 known albumins or albumoses, points out that it has in reality only 

 one property in common with the albumoses, viz., the solubility of its 

 precipitate on boiling. He has shown, however, that this is only 

 apparent, and that under suitable conditions the body is coagulated 

 on heating to 100 C., like the native albumins. He further noted 

 that, like the true albumins, the substance yields the common 

 digestive products of these bodies, viz., primary and secondary 

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